Aflsignor



Ap 9, 1929. F. c. KROEGER C IRCUIT BREAKER Original Filed April 1925 or, III

Patented A r. 9,1929.

UNITED STATES,

PATENT OFFICE.

' FREDERICK C. KROEGEE, OF ANDERSON, INDIAN A, ASSIGNOR,-BY MESNE ASSIGN MENTS, '10 DELCO-REMY CORPORATION, OF DAYTON, OHIO, A CORPORATION OF DELAWARE.

' CIRCUIT BREAKER.

, Application filed April 7, 1923, Serial No. 630,631. Renewed March 30, 1928.

This invention relates to a periodic circuit closer and more particularly to an ignition timer for internal-combustion engines.

. It is among the general objects of this invention to provide a cam operated circuit closer having: a self-lubricating rubbing block. 1

Another object of this invention is to reduce rebounding of the rubbing block from the cam.

Another object of this invention is the provision of acontact arm which can be rapidly formed from thin sheet metal whereby the cost of manufacture can be reduced.

present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of the present 1nvention is clearly shown.

In the drawings: v

Fig. 1 is a plan view of a periodic circuit closing apparatus showing my improved rubbing block and contact arm;

Fig. 2 is a side elevation of the periodic circuit closer looking in thedirection of the arrow 2 in Fig. 1;

Fig. 3 is a sectional view of the contact arm assembly taken on the line'33 of Fig. 1;

Fig. 4 is a sectional view of the contact arm taken on the line 4-4 of Fig. 1,"and a Fig. 5 is a top plan view of a sheet metal stamping which readily lends itself to the construction of a contact arm of the design shown in the preceding views, the folding lines being shown dotted.

The invention includes gcn'erally a periodic circuit closer or circuit breaker for an ignition system having a pair of contacts, a pivoted arm carrying one of said contacts and also a self-lubricating cam follower or rubbing block, and a cam. attached to a driven shaft, and adapted to cooperate with the cam follower or rubbing block. The self-lubricating cam follower is preferably of laminated construction consisting of laminations of wear resisting and non-conducting material such as micarta and a material which acts as a lubricant reservoir to supply'lubricant to the cam. This latter materialniay be any fibrous substance adapted retain a quantity of lubricant such as 'blottin paper saturated with a niixture of oil an jap'hite, commonly known as oil-dag. T e contact arm Further objects I and advantages of the is constructed from a sheet metal stamping and is so formed as to constitute a retaining means for the self-lubricating cam follower or rubbing block.

The mechanism herein illustrated is designed for use in connection with a six cylinder engine, but it should be understood, however, that the same is susceptible of applica-' tion, with slight modifications, to motors having any other number of explosion cylinders.

Thetype of ignition system in which I make use of the present invention is clearly shown in my copending v application filed November 6, 1922, Serial No. 599,238.

A blank 20, such as shown in Fig. 5, having' folding lines 21, 22, 23,24, 25, and 26, is

used in the construction of contact arm 30 shown in Fig. 3. It will be apparent that folding of the blank 20 on lines 21, 23, 24, and 25 will result in a U-shaped portion 31 of the contact arm 30. Folding on the line 26 will form upwardly extcnding'ear' 32 for supporting contact33 and folding on' the line 22 will form ear 34 which serves as a retaining means for the cam follower or rubbing block to be described later. The contact arm 30 is pierced at 27 to receive shank portion 35 of hub 36. Washer '37 fits-over shank 35 which isthen swaged down and serves as a rivet for holding .the washer and contact armin place.

' Base 50 receives the rotatable shaft' 51 on which is mounted cam 52. The base 50 has a hole which is countersunk as shown at 53 l to receive shank 54 of bushing 55. The shank 54 is swaged into the countersunk portion 53 andis held securely in place. The bushing 55 is reduced at 56 to receive coil spring 57. Shank 38 fits inside bushing 55 and is held in position by means of one end of. clip 58 pressing against shank 35, the other end of 05 said clip being held in place by means of screw 59 which on ages with a tapped hole in plate 50. One en of coil spring 57 is hooked over contact arm 30 as shown at 60, the opposite end being secured to screw 59. Main portion 61 of the contact arm 30 is recessed or grooved as shown at 62 and 63 at the same time that the bending operation of the blank 20 takes place in orderjto give added stiffness to the contact arm.

A bracket 70 for car ing stationary contact 71 is screwed to the ase 50 but insulated therefrom by means of insulating strip 72.

. laminations 81, 82, and 83. The laminations 81 and 82 are composed of thin strips of wear resisting and also non-conducting material such as micartaor its equivalent. The lami nation 83 is composed of a thin strip 'of material which may beany fibrous substance adapted to retain a quantity of lubricant such as blotting paper saturated with any suitable lubricant, preferably a mixture of oil and graphite, commonly known as oil-dag. Thus it will be seen thatthis blotting paper provides .a self-lubricating member which keeps the periphery of the cam 52 lubricated tending to reduce the Wear on the micarta laminations 81 and 82.

This cam follower is maintained in contact with the cam 52 at-all times by means of the tensionof the coil spring 57 bearing against the contact arm 30. To removethe contact arm 30, all that is necessary is to loosen the screw 59and swing the clip 58 around at approximately right angles and lift the contact arm 30 out. 1

Aside from its self-lubricating properties,

the cam follower or rubbing block absorbs to a substantial degree the force of impact of the cam striking against it, so that the high speed performance of the timer is substantiallyimproved. .This advantage is believed to result from the fact that the rubbing block is constructed so as to yield sidewise when struck by the cam. Since the stiff wear resisting portions 81 and 82 are relatively thin, either one of them may yield a substantial amount sidewise when struck by the cam 52. For example, assuming that the rotation of the cam is clockwise the cam will strike stiff lamination 82 causing it to bend toward .the right, as viewed in Fig. 1. It may yield in this direction because a relatively soft lamination83 is located between lamination 82 and lamination 81. Therefore a certain component of the force of impact of the cam against the follower is absorbed the soft derstood that and described constitutes'a preferred form of embodiment of the invention, it is to be another forms might be adopted, all coming within the scope of the claims which follow.

WhatI'claim is as follows:

1. In a periodic circuit closer, the combination with timer'contacts, of a rotating cam;- and a cam follower composed of fiexiblelaminations of wear resisting,- non-conducting' material and lubricating material interposed between the said laminations, said lubricating materialcomp'risin'g blotting paper saturated with lubricant.

2. In a periodic circuit closer, the combination with timercontacts; of a rotating cam; and a'cam follower-including a lamination ofv relatively compressible material located between r lativel stiff .wear resisting laminations for absor ing a. portion of the impact of the cam upon the follower.

3. In a periodic circuit closer, the combination withtimer contacts, .of a; rotating cam, and a. cam follower comprising laminations of wear resisting material and a layer of Inbricant'containing material between each of said laminae.

' 4. In aperiodic circuit'closer, the combina- 1 tion with timercontacts, of arotatingcam, and a'cam follower comprising laminations of wear resisting material and interposed between each two adjacent wear resisting lami nae, a. lamina of fibrous material saturated with a mixture of lubricating oil and graphite.

5. In a periodic circuit closer, the combination with timer contacts, of a rotating cam, and a cam followercomprising laminatlons of wear resisting material and interposed between each two adjacent wear resisting laminae, a lamina of blotting paper saturated with a lubricating material including graphite.

,In testimony whereof -I hereto allix my signature. 

